Re: problems with e1000 and jumboframes

[Krzysztof Oledzki <olel@ans.pl>]

On Thu, 3 Aug 2006, Evgeniy Polyakov wrote:
<CUT>
> > Why? After your explanation that makes sense for me. The driver needs
> > one contiguous chunk for those 9k packet buffer and thus requests a
> > 3-order page of 16k. Or do i still do not understand this?
>
> Correct, except that it wants 32k.
> e1000 logic is following:
> align frame size to power-of-two,
16K?

> then skb_alloc adds a little
> (sizeof(struct skb_shared_info)) at the end, and this ends up
> in 32k request just for 9k jumbo frame.

Strange, why this skb_shared_info cannon be added before first alignment? 
And what about smaller frames like 1500, does this driver behave similar 
(first align then add)?

Best regards,

				Krzysztof Olędzki